98 research outputs found

    Voltage controlled oscillator for mm-wave radio systems

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    Abstract. The advancement in silicon technology has accelerated the development of integrated millimeter-wave transceiver systems operating up to 100 GHz with sophisticated functionality at a reduced consumer cost. Due to the progress in the field of signal processing, frequency modulated continuous wave (FMCW) radar has become common in recent years. A high-performance local oscillator (LO) is required to generate reference signals utilized in these millimeter-wave radar transceivers. To accomplish this, novel design techniques in fundamental voltage controlled oscillators (VCO) are necessary to achieve low phase noise, wide frequency tuning range, and good power efficiency. Although integrated VCOs have been studied for decades, as we move higher in the radio frequency spectrum, there are new trade-offs in the performance parameters that require further characterization. The work described in this thesis aims to design a fully integrated fundamental VCO targeting to 150 GHz, i.e., D-Band. The purpose is to observe and analyze the design limitations at these high frequencies and their corresponding trade-offs during the design procedure. The topology selected for this study is the cross-coupled LC tank VCO. For the study, two design topologies were considered: a conventional cross-coupled LC tank VCO and an inductive divider cross-coupled LC tank VCO. The conventional LC tank VCO yields better performance in terms of phase noise and tuning range. It is observed that the VCO is highly sensitive to parasitic contributions by the transistors, and the layout interconnects, thus limiting the targeted frequency range. The dimensions of the LC tank and the transistors are selected carefully. Moreover, the VCO performance is limited by the low Q factor of the LC tank governed by the varactor that is degrading the phase noise performance and the tuning range, respectively. The output buffer loaded capacitance and the core power consumption of the VCO are optimized. The layout is drawn carefully with strategies to minimize the parasitic effects. Considering all the design challenges, a 126 GHz VCO with a tuning range of 3.9% is designed. It achieves FOMT (Figure-of-merit) of -172 dBc/Hz, and phase noise of -99.14 dBc/Hz at 10 MHz offset, Core power consumption is 8.9 mW from a 1.2 V supply. Just falling short of the targeted frequency, the design is suitable for FMCW radar applications for future technologies. The design was done using Silicon-on-Insulator (SOI) CMOS technology

    Survey on individual components for a 5 GHz receiver system using 130 nm CMOS technology

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    La intención de esta tesis es recopilar información desde un punto de vista general sobre los diferentes tipos de componentes utilizados en un receptor de señales a 5 GHz utilizando tecnología CMOS. Se ha realizado una descripción y análisis de cada uno de los componentes que forman el sistema, destacando diferentes tipos de configuraciones, figuras de mérito y otros parámetros. Se muestra una tabla resumen al final de cada sección, comparando algunos diseños que se han ido presentando a lo largo de los años en conferencias internacionales de la IEEE.The intention of this thesis is to gather information from an overview point about the different types of components used in a 5 GHz receiver using CMOS technology. A review of each of the components that form the system has been made, highlighting different types of configurations, figure of merits and parameters. A summary table is shown at the end of each section, comparing many designs that have been presented over the years at international conferences of the IEEE.Departamento de Ingeniería Energética y FluidomecánicaGrado en Ingeniería en Electrónica Industrial y Automátic

    Transition Frequencies and Negative Resistance of Inductively Terminated CMOS Buffer Cell and Application in MMW LC VCO

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    This paper investigates the transition frequencies (trans) of an inductively terminated CMOS source follower buffer for negative resistance behavior at which the effective shunt resistance looking into the source of the buffer cell changes sign. Possible limiting frequencies of oscillation are determined based on resonators formed by a grounded gate inductor and a parasitic capacitance at the gate of the negative resistance buffer cell. The range of frequencies of oscillation of this negative resistance buffer cell for variations in the different circuit parameters/elements is explored. Following this, a millimeter wave (MMW) oscillator is simulated using the IBM 130 nm CMOS process technology which can operate at 70 GHz. High-frequency MOSFET model was used for these simulations. The cell had an extremely low power dissipation of under 3 mW. Extensive Monte Carlo simulations were carried out for manufacturability analysis considering up to 50% variation in process and geometrical parameters, supply voltage, and ambient temperature. Noise analysis and a simulated estimate of the phase noise in an MMW LC VCO application is also reported

    Low power digitally controlled oscillator for IoT applications

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    This work is focused on the design of a Low Power CMOS DCO for IEEE 802.11ah in IoT applications. The design methodology is based on the Unified current-control model (UICM), which is a physics-based model and enables an accurate all-region model of the operation of the device. Additionally, a transformer-based resonator has been used to solve the low-quality factor issue of integrated inductors. Two digitally controlled oscillators (DCO) have been implemented to show the advantages of utilizing a transformedbased resonator and the methodology based on the UICM model. These designs aim for the operation in low voltage supply (VDD) since VDD scaling is a trend in systems-onchip (SoCs), in which the circuitry is mostly digital. Despite the degradation caused by VDD scaling, new RF and analog circuits must deliver similar performance of the older CMOS nodes. The first DCO design was a low power LC-tank DCO, implemented in 40nm bulk-CMOS. The first design presented a DCO operating at 45% of the nominal VDD without compromise the performance. By reducing the VDD below the nominal value, this DCO reduces power consumption, which is a crucial feature for IoT circuits. The main contribution of this first DCO is the reduction of VDD scaling impact on the phase-noise do the DCO. The LC-based DCO operates from 1.8 to 1.86 GHz. At the maximum frequency and 0.395V VDD, the power consumption is a mere 380 W with a phase-noise of -119.3 dBc/Hz at 1 MHz. The circuit occupies an area of 0.46mm2 in 40 nm CMOS, mostly due to the inductor. The second DCO design was a low-power transformer-based DCO design, implemented in 28nm bulk-CMOS. This second design aims for the VDD reduction to below 0.3 V. Operating in a frequency range similar to the LC-based DCO, the transformer-based DCO operated with 0.280V VDD with a power consumption of 97 W. Meanwhile, the phase-noise was -101.95 dBc/Hz at 1 MHz. Even in the worst-case scenario (i.e., slow-slow and 85oC), this second DCO was able to operate at 0.330V VDD, consuming 126 W, while it keeps a similar phase-noise performance of the typical case. The core circuit occupies an area of 0.364 mm2.Este trabalho objetiva o projeto de um DCO de baixa potência em CMOS para aplicações de IoT e aderentes ao padrão IEEE 802.11ah. A metodologia de projeto é baseada no modelo de controle de corrente unificado (UICM), que é um modelo com embasamento físico que permite uma operação precisa em todas as regiões de operação do dispositivo. Adicionalmente, é utilizado um ressonador baseado em transformador visando solucionar os problemas provenientes do baixo fator de qualidade de indutores integrados. Para destacar as melhorias obtidas com o projeto do ressonador baseado em transformador e com a metodologia baseada no modelo UICM, dois projetos de DCO são realizados. Esses projetos visam a operação com baixa tensão de alimentação (VDD), uma vez que o escalonamento do VDD é uma tendência em sistemas em chip (SoCs), em que o circuito é majoritariamente digital. Independente da degradação causada pelo escalonamento de VDD, circuitos analógicos e de RF atuais devem oferecer desempenho semelhante ao alcançado em tecnologias CMOS mais antigas. O primeiro projeto foi um DCO de baixa potência com tanque LC, implementado em tecnologia bulk-CMOS de 40nm. O primeiro projeto apresentou uma operação a 45% do VDD nominal sem comprometer o desempenho. Ao reduzir o VDD abaixo do valor nominal, este DCO reduz o consumo de energia, que é uma característica crucial para circuitos IoT. A principal contribuição deste DCO é a redução do impacto do escalonamento do VDD no ruído de fase. O DCO com tanque LC opera de 1,8 a 1,86 GHz. Na frequência máxima e com VDD de apenas 0,395V, o consumo de energia é 380 W e o ruído de fase é -119,3 dBc/Hz a 1 MHz. O circuito ocupa uma área de 0.46mm2 em processo CMOS de 40 nm. O segundo projeto foi um DCO de baixa potência baseado em transformador, implementado em tecnologia bulk- CMOS de 28nm. Este projeto visa a redução de VDD abaixo de 0,3 V. Operando em uma faixa de frequência semelhante ao primeiro DCO, o DCO baseado em transformador opera com VDD de 0,280V e com consumo de potência de 97 W. O ruído de fase foi de -101,95 dBc/Hz a 1 MHz. Mesmo no pior caso de processo, este DCO opera a um VDD de 0,330V, consumindo 126 W, com o ruído de fase semelhante ao caso típico. O circuito ocupa uma área de 0.364mm2

    Design And Implementation Of Up-Conversion Mixer And Lc-Quadrature Oscillator For IEEE 802.11a WLAN Transmitter Application Utilizing 0.18 Pm CMOS Technology [TK7871.99.M44 H279 2008 f rb].

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    Perlumbaan implementasi litar terkamil radio, dengan kos yang rendah telah menggalakkan penggunaan teknologi CMOS. The drive for cost reduction has led to the use of CMOS technology for highly integrated radios

    Design of CMOS integrated frequency synthesizers for ultra-wideband wireless communications systems

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    Ultra¬wide band (UWB) system is a breakthrough in wireless communication, as it provides data rate one order higher than existing ones. This dissertation focuses on the design of CMOS integrated frequency synthesizer and its building blocks used in UWB system. A mixer¬based frequency synthesizer architecture is proposed to satisfy the agile frequency hopping requirement, which is no more than 9.5 ns, three orders faster than conventional phase¬locked loop (PLL)¬based synthesizers. Harmonic cancela¬tion technique is extended and applied to suppress the undesired harmonic mixing components. Simulation shows that sidebands at 2.4 GHz and 5 GHz are below 36 dBc from carrier. The frequency synthesizer contains a novel quadrature VCO based on the capacitive source degeneration structure. The QVCO tackles the jeopardous ambiguity of the oscillation frequency in conventional QVCOs. Measurement shows that the 5¬GHz CSD¬QVCO in 0.18 µm CMOS technology draws 5.2 mA current from a 1.2 V power supply. Its phase noise is ¬120 dBc at 3 MHz offset. Compared with existing phase shift LC QVCOs, the proposed CSD¬QVCO presents better phase noise and power efficiency. Finally, a novel injection locking frequency divider (ILFD) is presented. Im¬plemented with three stages in 0.18 µm CMOS technology, the ILFD draws 3¬mA current from a 1.8¬V power supply. It achieves multiple large division ratios as 6, 12, and 18 with all locking ranges greater than 1.7 GHz and injection frequency up to 11 GHz. Compared with other published ILFDs, the proposed ILFD achieves the largest division ratio with satisfactory locking range

    Frequency Synthesizers and Oscillator Architectures Based on Multi-Order Harmonic Generation

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    Frequency synthesizers are essential components for modern wireless and wireline communication systems as they provide the local oscillator signal required to transmit and receive data at very high rates. They are also vital for computing devices and microcontrollers as they generate the clocks required to run all the digital circuitry responsible for the high speed computations. Data rates and clocking speeds are continuously increasing to accommodate for the ever growing demand on data and computational power. This places stringent requirements on the performance metrics of frequency synthesizers. They are required to run at higher speeds, cover a wide range of frequencies, provide a low jitter/phase noise output and consume minimum power and area. In this work, we present new techniques and architectures for implementing high speed frequency synthesizers which fulfill the aforementioned requirements. We propose a new architecture and design approach for the realization of wideband millimeter-wave frequency synthesizers. This architecture uses two-step multi-order harmonic generation of a low frequency phase-locked signal to generate wideband mm-wave frequencies. A prototype of the proposed system is designed and fabricated in 90nm Complementary Metal Oxide Semiconductor (CMOS) technology. Measurement results demonstrated that a very wide tuning range of 5 to 32 GHz can be achieved, which is costly to implement using conventional techniques. Moreover the power consumption per octave resembles that of state-of-the art reports. Next, we propose the N-Push cyclic coupled ring oscillator (CCRO) architecture to implement two high performance oscillators: (1) a wideband N-Push/M-Push CCRO operating from 3.16-12.8GHz implemented by two harmonic generation operations using the availability of different phases from the CCRO, and (2) a 13-25GHz millimeter-wave N-Push CCRO with a low phase noise performance of -118dBc/Hz at 10MHz. The proposed oscillators achieve low phase noise with higher FOM than state of the art work. Finally, we present some improvement techniques applied to the performance of phase locked loops (PLLs). We present an adaptive low pass filtering technique which can reduce the reference spur of integer-N charge-pump based PLLs by around 20dB while maintaining the settling time of the original PLL. Another PLL is presented, which features very low power consumption targeting the Medical Implantable Communication Standard. It operates at 402-405 MHz while consuming 600microW from a 1V supply
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